This asynchronous operation returns a \code{Deferred} object with a
\code{waitForIt} method which blocks and returns an object indicating the
success or failure of the operation.  Valid values to be returned are:

\begin{itemize}[noitemsep]
\item The returned object, represented as a map from attributes' names to Java
    objects.
\item \code{False} if any provided predicates failed.
\item \code{null} if the operation requires an existing value and none exists
\end{itemize}

On error, this function will raise a \code{HyperDexClientException} describing
the error.
